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			<h1>common_schema</h1> <strong>2.2</strong> documentation
			<div class="subtitle">DBA's framework for MySQL</div>
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				<h2><a href="variables.html">variables</a></h2>	
<h3>SYNOPSIS</h3>

<p>
User defined variables used as input to <i>common_schema</i> routines, 
or are the output of routines.
</p>
<p>
Input variables:
<ul>
	<li><a href="#common_schema_debug">@common_schema_verbose</a>: set verbose messages</li>
	<li><a href="#common_schema_dryrun">@common_schema_dryrun</a>: avoid dynamic query execution</li>
	<li><a href="#common_schema_debug">@common_schema_debug</a>: set debug mode</li>
</ul>
</p>
<p>
Output variables:
<ul>
	<li><a href="#common_schema_rowcount">@common_schema_rowcount</a>: number of rows affected by last dynamic query</li>
	<li><a href="#common_schema_error">@common_schema_error</a>: latest error message</li>
</ul>
</p>

<h3>DESCRIPTION</h3>
<p>
	<strong>@common_schema_verbose</strong> and <strong>@common_schema_dryrun</strong> both serve as input to <a href="exec_single.html">exec_single()</a>,
	which is a basic function in <i>common_schema</i> for dynamic query execution. <i>eval()</i>, <i>exec()</i>, <i>foreach()</i>, 
	<i>repeat_exec()</i>, <i>run()</i> -- all rely on <i>exec_single()</i>, hence these two params affect all aforementioned functions.
</p>
<p>
	Setting <strong>@common_schema_dryrun := 1</strong> avoids executing dynamic queries issues by <i>exec_single()</i>. This makes for
	a way to test your code before execution.
</p>
<p>
	Setting <strong>@common_schema_verbose := 1</strong> prints out executed queries, and serves as a verbose mode for your code's activity.	
</p>
<p>
	Setting <strong>@common_schema_debug := 1</strong> will enable some internal debugging code. The particulars are subject to change, but you
	may find it useful.
</p>
<p>
	When issuing queries such as <strong>INSERT, DELETE, UPDATE</strong> via dynamic SQL, the <a href="http://dev.mysql.com/doc/refman/5.1/en/information-functions.html#function_row-count"><strong>ROW_COUNT()</strong></a> function does not behave as expected,
	since the <strong>DEALLOCATE</strong> statement resets it.
	This is why after each invocation of dynamic query via <i>exec_single()</i>, the <strong>@common_schema_rowcount</strong> variable is set so as to
	reflect the <strong>ROW_COUNT()</strong> as read immediately after invocation. 
</p>
<p>
	<strong>@common_schema_error</strong> can be set by various functionality upon error. In particular, it is set by the <a href="throw.html">throw()</a>
	routine to the error message provided. 
</p>


<h3>NOTES</h3>
<p>
	<i>common_schema</i> utilized many more variables, internally. Internal user defined variables are named, by convention, 
	<strong>@_common_schema_*</strong>. You should refrain from depending on the output of any such variable, nor should you modify such
	variables. 
</p>
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					<h3>DATA</h3>
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